Burkholderia is a genus of proteobacteria known for its pathogenic members: Burkholderia mallei, responsible for glanders, a disease that occurs mostly in horses and related animals; Burkholderia pseudomallei, causative agent of melioidosis; and the Burkholderia cepacia complex, which includes pathogens that are involved in pulmonary infections of people with cystic fibrosis (CF). The Burkholderia genus name refers to a group of common gram-negative, motile, obligately aerobic rod-shaped bacteria including animal, human, and plant pathogens. Due to their antibiotic resistance and the high mortality rate from their associated diseases, Burkholderia mallei and Burkholderia pseudomallei are considered to be potential biological warfare agents, with livestock and humans as potential targets.
Humans and animals are believed to acquire Burkholderia infection by inhalation of contaminated dust or water droplets, ingestion of contaminated water, and contact with contaminated soil, especially through skin abrasions.
Many non-human animal species can be susceptible to melioidosis caused by Burkholderia pseudomallei, including many livestock and/or companion animal species such as, for example, sheep, goats, horses, swine, cattle, dogs, and cats.
In the absence of treatment with appropriate antibiotics, the septicemic form of melioidosis has a mortality rate that exceeds 90%. With appropriate antibiotic treatment, the mortality rate is about 10% for uncomplicated cases but up to 80% for cases with bacteremia or severe sepsis. Because of its severe course of infection, aerosol infectivity, and worldwide availability, B. pseudomallei is identified as a potential agent of biological warfare or bioterrorism and is listed on the Centers for Disease Control list as a Category B bioterrorism agent. There is currently no vaccine and the organism is often refractory to antibiotic therapy, especially after it is established in a host.